When you turned, was it the foot you stood on which is popping now? Did/does it swell up? Where does/did it hurt? Can/could you fully extend your knee and bend it fully? Does your knee lock sometimes? Is the knee warm? You see you don't give enough information to help you. Popping can be meniscus, ITB, Patella and sometimes the hip (while you think it is the knee) So describe as good as you can how it happened, where you feel pain and so on.